Calculator Net Pregnancy Weight Gain

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Net Pregnancy Weight Gain Calculator

Monitor your healthy weight progression during pregnancy.

Pregnancy Weight Gain Tracker

Enter your weight before pregnancy in kilograms (kg).
Enter your current weight in kilograms (kg).
Enter the number of weeks pregnant (e.g., 28).

Your Net Pregnancy Weight Gain

0.0 kg

Weekly Gain: 0.0 kg/week
Lower Target: — kg
Upper Target: — kg

Net Pregnancy Weight Gain is calculated by subtracting your pre-pregnancy weight from your current weight. Target ranges are based on general recommendations for a healthy pregnancy, considering gestational age and pre-pregnancy BMI categories.

Weight Gain Trend Visualization

This chart shows your current weight gain relative to typical healthy ranges throughout pregnancy.

Typical Pregnancy Weight Gain Table

Trimester Weeks Recommended Gain (Total) Recommended Gain (Weekly Average)
1st 1-13 ~1.5 – 2.5 kg ~0.25 – 0.5 kg/week
2nd 14-27 ~6.5 – 7.5 kg ~0.5 – 1.0 kg/week
3rd 28-40 ~12.5 – 18 kg ~0.5 – 1.0 kg/week

These are general guidelines for total weight gain by the end of each trimester. Individual needs may vary.

What is Net Pregnancy Weight Gain?

Net pregnancy weight gain refers to the total amount of weight a pregnant individual has gained from the beginning of their pregnancy up to the current point. This calculation is crucial for monitoring the health of both the mother and the developing baby. Healthy weight gain during pregnancy is essential, as insufficient gain can lead to low birth weight and premature birth, while excessive gain can increase the risk of complications like gestational diabetes, preeclampsia, and a Cesarean delivery. Understanding your net pregnancy weight gain helps ensure you are on a healthy trajectory.

Who Should Use It? Any pregnant individual seeking to track their weight progression and ensure it aligns with recommended guidelines should use a net pregnancy weight gain calculator. It's a simple yet powerful tool for proactive health management throughout gestation. It can also be beneficial for healthcare providers to quickly assess a patient's weight status.

Common Misconceptions: A common misconception is that all weight gain during pregnancy is "baby weight." However, pregnancy weight gain includes the baby, placenta, amniotic fluid, increased breast tissue, increased blood volume, extra body fat stores, and amniotic fluid. Another misconception is that "eating for two" means doubling food intake, which is generally not necessary until the third trimester and even then, requires mindful choices, not simply doubling calories.

Net Pregnancy Weight Gain Formula and Mathematical Explanation

The calculation for net pregnancy weight gain is straightforward but relies on accurate input data. The primary goal is to determine the difference between the current weight and the pre-pregnancy weight. This difference represents the total maternal and fetal weight changes accumulated over the course of the pregnancy.

The Core Formula: Net Pregnancy Weight Gain = Current Weight - Pre-Pregnancy Weight

Calculating Average Weekly Gain: To understand the pace of weight gain, we can calculate the average weekly gain. Average Weekly Gain = Net Pregnancy Weight Gain / Gestational Age (in weeks)

Estimating Target Ranges: Recommended weight gain targets vary based on the individual's pre-pregnancy Body Mass Index (BMI). For simplicity in this calculator, we use generalized targets. A common recommendation for a healthy BMI (18.5-24.9) is a total gain of 11.5-16 kg (25-35 lbs). * Lower Target Range (e.g., for a total gain of 11.5 kg): Lower Target = Pre-Pregnancy Weight + 11.5 kg * Upper Target Range (e.g., for a total gain of 16 kg): Upper Target = Pre-Pregnancy Weight + 16 kg These ranges are approximations and should be discussed with a healthcare provider.

Variable Explanations

Variable Meaning Unit Typical Range
Pre-Pregnancy Weight Weight before conception. kg 45 – 120+
Current Weight Weight at the current stage of pregnancy. kg Varies based on pre-pregnancy weight and gain.
Gestational Age Duration of pregnancy in weeks. weeks 1 – 40
Net Pregnancy Weight Gain Total weight gained since conception. kg 0 – 25+
Average Weekly Gain Average gain per week of pregnancy. kg/week 0.2 – 1.0+
Target Range (Lower/Upper) Recommended total weight gain boundaries. kg 11.5 – 16 (for healthy BMI)

Accurate measurements are key to reliable results. Always consult your doctor for personalized advice.

Practical Examples (Real-World Use Cases)

Let's illustrate how the Net Pregnancy Weight Gain Calculator works with realistic scenarios.

Example 1: Healthy BMI Individual

Sarah, who had a healthy Body Mass Index (BMI) before pregnancy, is now 30 weeks pregnant. Her pre-pregnancy weight was 60 kg. Currently, she weighs 71 kg.

  • Inputs:
  • Pre-Pregnancy Weight: 60 kg
  • Current Weight: 71 kg
  • Gestational Age: 30 weeks

Calculation: Net Pregnancy Weight Gain = 71 kg – 60 kg = 11 kg Average Weekly Gain = 11 kg / 30 weeks ≈ 0.37 kg/week Lower Target Range (assuming 11.5 kg total): 60 kg + 11.5 kg = 71.5 kg Upper Target Range (assuming 16 kg total): 60 kg + 16 kg = 76 kg

Interpretation: Sarah has gained 11 kg by 30 weeks. Her average weekly gain is about 0.37 kg/week. She is currently at the lower end of the ideal total weight gain range for someone with a healthy pre-pregnancy BMI, which is generally between 11.5 kg and 16 kg. Her current weight is within the expected range for her gestational age.

Example 2: Individual with Higher Pre-Pregnancy Weight

Maria, whose pre-pregnancy weight was 85 kg (indicating a higher BMI category), is 24 weeks pregnant. Her current weight is 92 kg.

  • Inputs:
  • Pre-Pregnancy Weight: 85 kg
  • Current Weight: 92 kg
  • Gestational Age: 24 weeks

Calculation: Net Pregnancy Weight Gain = 92 kg – 85 kg = 7 kg Average Weekly Gain = 7 kg / 24 weeks ≈ 0.29 kg/week *Note: For higher BMI categories, the recommended total weight gain is typically lower (e.g., 7-11.5 kg). The calculator provides general targets; a doctor's advice is paramount.* Lower Target Range (general, assuming ~7 kg for this BMI): 85 kg + 7 kg = 92 kg Upper Target Range (general, assuming ~11.5 kg for this BMI): 85 kg + 11.5 kg = 96.5 kg

Interpretation: Maria has gained 7 kg at 24 weeks. Her average weekly gain is about 0.29 kg/week. For individuals with higher pre-pregnancy BMI, the recommended total gain is less. Her current gain is within the lower end of the typical range for her BMI category. It's crucial for Maria to discuss her specific weight gain targets with her obstetrician, as recommendations are tailored to individual health profiles.

How to Use This Net Pregnancy Weight Gain Calculator

Our Net Pregnancy Weight Gain Calculator is designed for simplicity and ease of use, providing valuable insights into your pregnancy health journey.

  1. Gather Your Information: You will need three key pieces of information:
    • Your weight before you became pregnant (Pre-Pregnancy Weight in kg).
    • Your current weight (Current Weight in kg).
    • Your current stage of pregnancy, measured in weeks (Gestational Age in weeks).
  2. Input the Data: Enter each value into the corresponding field in the calculator. Ensure you use kilograms for weight and whole numbers for weeks.
  3. Click Calculate: Once your information is entered, click the "Calculate" button. The calculator will instantly process your inputs.
  4. Review Your Results:
    • Net Pregnancy Weight Gain: This is your primary result, showing the total weight you've gained so far.
    • Weekly Gain: This indicates your average rate of weight gain per week.
    • Target Range (Lower/Upper): These values provide a general guideline for a healthy total weight gain for someone with a normal pre-pregnancy BMI.
  5. Understand the Chart and Table: The accompanying dynamic chart and table offer visual and tabular representations of recommended weight gain patterns throughout pregnancy, helping you contextualize your results.
  6. Copy Results: If you wish to share your results or keep a record, use the "Copy Results" button. This will copy the main result, intermediate values, and key assumptions to your clipboard.
  7. Reset: The "Reset" button clears all fields and returns them to sensible default values, allowing you to start a new calculation easily.

Decision-Making Guidance: This calculator is an informational tool. If your results fall significantly outside the suggested ranges, or if you have concerns about your weight gain, it is crucial to consult with your healthcare provider. They can offer personalized advice based on your unique health status, medical history, and specific pregnancy needs.

Key Factors That Affect Pregnancy Weight Gain Results

While the calculator provides a quantitative measure of net pregnancy weight gain, several factors influence this number and its implications. Understanding these can provide a more holistic view of maternal health.

  • Pre-Pregnancy BMI: This is arguably the most significant factor determining recommended weight gain. Individuals who are underweight are typically advised to gain more weight, while those who are overweight or obese are advised to gain less to mitigate health risks for both mother and baby. Our calculator uses general targets, but a doctor will personalize this.
  • Maternal Age: While not directly in the formula, advanced maternal age can sometimes be associated with different physiological responses and potentially influence weight management strategies and recommendations.
  • Multiple Gestations (Twins, Triplets, etc.): Carrying more than one baby naturally requires a higher overall weight gain and a different pattern of gain throughout the pregnancy compared to a singleton pregnancy.
  • Maternal Health Conditions: Pre-existing conditions like diabetes, hypertension, or thyroid disorders, as well as pregnancy-specific conditions like gestational diabetes or preeclampsia, can significantly impact weight gain recommendations and patterns. Fluid retention associated with some conditions can also artificially inflate current weight.
  • Dietary Intake and Quality: The type and quantity of food consumed directly impact weight gain. A balanced diet rich in nutrients is essential for healthy fetal development and appropriate maternal weight gain, avoiding excessive intake of empty calories. Proper nutrition is key to healthy pregnancy nutrition.
  • Physical Activity Levels: Regular, moderate exercise contributes to healthy weight management during pregnancy. It helps burn calories, build strength, and can prevent excessive weight gain, while also offering numerous other health benefits. Engaging in safe prenatal exercises is beneficial.
  • Individual Metabolism and Genetics: Like any aspect of health, individual metabolic rates and genetic predispositions can play a role in how efficiently a body utilizes nutrients and stores fat, influencing weight gain patterns.
  • Socioeconomic Factors: Access to healthy foods, safe environments for exercise, and regular healthcare can be influenced by socioeconomic status, indirectly affecting weight management during pregnancy. Understanding maternal health resources is vital.

Frequently Asked Questions (FAQ)

What is considered a healthy amount of weight gain in the first trimester?
In the first trimester (weeks 1-13), weight gain is typically modest, often around 1.5 to 2.5 kg (3 to 5 lbs). Some individuals may even lose weight due to morning sickness. The focus is on nutrition rather than significant weight gain.
How much weight should I gain per week in the second and third trimesters?
For individuals with a healthy pre-pregnancy BMI, the recommended rate of gain is generally about 0.5 kg (1 lb) per week during the second and third trimesters. This can be slightly higher or lower depending on individual factors and overall target gain.
What if my current weight gain is higher than recommended?
If you are gaining weight faster than recommended, it's important to consult your healthcare provider. They can help identify potential causes, such as increased fluid retention or dietary habits, and suggest appropriate dietary modifications or lifestyle adjustments. Excessive gain increases risks like gestational diabetes.
What if my current weight gain is lower than recommended?
Insufficient weight gain can be concerning as it may indicate inadequate calorie intake or nutrient absorption, potentially affecting fetal growth. Discuss this with your doctor, who may recommend dietary changes or further investigation. Explore prenatal nutrition tips for guidance.
Does the calculator account for BMI?
This calculator provides general target ranges based on typical recommendations for a healthy pre-pregnancy BMI. It does not calculate BMI itself. For personalized targets based on your specific BMI category (underweight, normal, overweight, obese), consult your healthcare provider.
What are the components of pregnancy weight gain?
Pregnancy weight gain comprises several components: the fetus, placenta, amniotic fluid, uterus growth, increased breast tissue, increased blood volume, increased extracellular fluid, and maternal fat stores.
Can I use this calculator if I'm pregnant with twins?
This calculator is designed for singleton pregnancies. Weight gain recommendations differ significantly for multiple gestations (twins, triplets, etc.). You should consult your healthcare provider for specific guidelines for carrying multiples.
How accurate are the target ranges provided?
The target ranges provided are general guidelines based on common recommendations for a healthy pre-pregnancy BMI. Individual needs can vary considerably. Always rely on the advice of your obstetrician or midwife for personalized weight gain goals. Understanding pregnancy complications can also highlight the importance of appropriate weight gain.

© 2023 Your Health Insights. All rights reserved.

Disclaimer: This calculator is for informational purposes only and does not constitute medical advice. Consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.

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errorElement.classList.add("visible"); } } function hideError(elementId) { var errorElement = document.getElementById(elementId); if (errorElement) { errorElement.textContent = ""; errorElement.classList.remove("visible"); } } function calculateBMI(weightKg, heightCm) { if (!weightKg || !heightCm) return null; var heightM = heightCm / 100; return weightKg / (heightM * heightM); } function getWeightGainTargets(prePregnancyWeightKg, bmiCategory) { var totalGainLower = 11.5; // Default for healthy BMI var totalGainUpper = 16.0; // Default for healthy BMI if (bmiCategory === 'underweight') { totalGainLower = 12.7; totalGainUpper = 18.1; } else if (bmiCategory === 'overweight') { totalGainLower = 7.0; totalGainUpper = 11.3; } else if (bmiCategory === 'obese') { totalGainLower = 5.0; // Or as recommended by doctor totalGainUpper = 9.0; // Or as recommended by doctor } // For normal BMI, defaults are used. var lowerTarget = prePregnancyWeightKg + totalGainLower; var upperTarget = prePregnancyWeightKg + totalGainUpper; return { lower: lowerTarget.toFixed(1), upper: upperTarget.toFixed(1) }; } function getBMICategory(bmi) { if (bmi = 18.5 && bmi = 25 && bmi = 30) return 'obese'; return 'unknown'; } function calculateNetGain() { var prePregnancyWeight = parseFloat(prePregnancyWeightInput.value); var currentWeight = parseFloat(currentWeightInput.value); var gestationalAge = parseInt(gestationalAgeInput.value, 10); // Input validation var valid = true; if (!isValidNumber(prePregnancyWeight) || prePregnancyWeight <= 0) { showError("prePregnancyWeightError", "Please enter a valid pre-pregnancy weight."); valid = false; } else { hideError("prePregnancyWeightError"); } if (!isValidNumber(currentWeight) || currentWeight <= 0) { showError("currentWeightError", "Please enter a valid current weight."); valid = false; } else { hideError("currentWeightError"); } if (!isValidNumber(gestationalAge) || gestationalAge 40) { showError("gestationalAgeError", "Please enter a valid gestational age between 1 and 40 weeks."); valid = false; } else { hideError("gestationalAgeError"); } if (!valid) { // Reset results if validation fails mainResultDisplay.textContent = "0.0 kg"; weightGainPerWeekDisplay.textContent = "0.0 kg/week"; targetRangeLowerDisplay.textContent = "– kg"; targetRangeUpperDisplay.textContent = "– kg"; updateChart([0], [0], [0], [0]); // Clear chart return; } var netWeightGain = currentWeight – prePregnancyWeight; var averageWeeklyGain = netWeightGain / gestationalAge; // For target range estimation, we'll use a simplified approach assuming a healthy BMI for demonstration. // A real-world calculator might ask for height/BMI directly. // Let's assume a default healthy BMI category for now. // A more robust solution would require height input to calculate BMI. // For this example, we'll use the general targets mentioned in the article. var lowerTargetKg = prePregnancyWeight + 11.5; var upperTargetKg = prePregnancyWeight + 16.0; mainResultDisplay.textContent = netWeightGain.toFixed(1) + " kg"; weightGainPerWeekDisplay.textContent = averageWeeklyGain.toFixed(2) + " kg/week"; targetRangeLowerDisplay.textContent = lowerTargetKg.toFixed(1) + " kg"; targetRangeUpperDisplay.textContent = upperTargetKg.toFixed(1) + " kg"; // Update chart updateChartData(prePregnancyWeight, gestationalAge, currentWeight); } function resetCalculator() { prePregnancyWeightInput.value = defaultValues.prePregnancyWeight; currentWeightInput.value = defaultValues.currentWeight; gestationalAgeInput.value = defaultValues.gestationalAge; // Clear errors hideError("prePregnancyWeightError"); hideError("currentWeightError"); hideError("gestationalAgeError"); calculateNetGain(); // Recalculate with default values } function copyResults() { var mainResult = mainResultDisplay.textContent; var weeklyGain = weightGainPerWeekDisplay.textContent; var lowerTarget = targetRangeLowerDisplay.textContent; var upperTarget = targetRangeUpperDisplay.textContent; var assumptions = "Key Assumptions:\n"; assumptions += "- Pre-Pregnancy Weight: " + prePregnancyWeightInput.value + " kg\n"; assumptions += "- Current Weight: " + currentWeightInput.value + " kg\n"; assumptions += "- Gestational Age: " + gestationalAgeInput.value + " weeks\n"; assumptions += "- Target ranges are general estimates for healthy BMI.\n"; var textToCopy = "Net Pregnancy Weight Gain Results:\n\n"; textToCopy += "Net Gain: " + mainResult + "\n"; textToCopy += "Average Weekly Gain: " + weeklyGain + "\n"; textToCopy += "Target Range: " + lowerTarget + " – " + upperTarget + "\n\n"; textToCopy += assumptions; navigator.clipboard.writeText(textToCopy).then(function() { // Optionally show a confirmation message alert("Results copied to clipboard!"); }, function(err) { console.error("Failed to copy results: ", err); // Fallback for older browsers or if clipboard API fails var textArea = document.createElement("textarea"); textArea.value = textToCopy; textArea.style.position = "fixed"; // Avoid scrolling to bottom document.body.appendChild(textArea); textArea.focus(); textArea.select(); try { var successful = document.execCommand('copy'); var msg = successful ? 'successful' : 'unsuccessful'; console.log('Fallback: Copying text command was ' + msg); alert("Results copied to clipboard (fallback method)!"); } catch (err) { console.error('Fallback: Oops, unable to copy', err); alert("Could not copy results. Please copy manually."); } document.body.removeChild(textArea); }); } // Charting Logic function updateChartData(prePregnancyWeight, gestationalAge, currentWeight) { var ctx = document.getElementById('weightGainChart').getContext('2d'); // Simulate data points for a typical pregnancy curve // This is a simplified representation var weeks = []; var idealGain = []; // Represents ideal total gain at each week var lowerBound = []; // Lower end of recommended total gain var upperBound = []; // Upper end of recommended total gain var actualGain = []; // Actual total gain so far var totalGain = currentWeight – prePregnancyWeight; var weeksOfPregnancy = gestationalAge; // Generate weekly data points up to 40 weeks for (var i = 1; i <= 40; i++) { weeks.push(i); var currentIdealTotalGain; var currentLowerBound; var currentUpperBound; // Simplified ideal gain progression (based on general guidelines) if (i <= 13) { // First Trimester currentIdealTotalGain = prePregnancyWeight + (i / 13) * 2.0; // ~2kg gain currentLowerBound = prePregnancyWeight + 1.5; currentUpperBound = prePregnancyWeight + 2.5; } else if (i <= 27) { // Second Trimester var gainIn2ndTrimester = (i – 13) / (27 – 13) * 6.0; // ~6kg gain in 2nd currentIdealTotalGain = prePregnancyWeight + 2.0 + gainIn2ndTrimester; currentLowerBound = prePregnancyWeight + 2.5 + ((i – 13) / 14) * 5.0; // 2.5 + ~5kg currentUpperBound = prePregnancyWeight + 2.5 + ((i – 13) / 14) * 5.0; // 2.5 + ~5kg } else { // Third Trimester var gainIn3rdTrimester = (i – 27) / (40 – 27) * 6.0; // ~6kg gain in 3rd currentIdealTotalGain = prePregnancyWeight + 8.0 + gainIn3rdTrimester; currentLowerBound = prePregnancyWeight + 7.5 + ((i – 27) / 13) * 4.5; // 7.5 + ~4.5kg currentUpperBound = prePregnancyWeight + 7.5 + ((i – 27) / 13) * 4.5; // 7.5 + ~4.5kg } // Ensure bounds are reasonable and follow typical total gain patterns currentLowerBound = Math.max(currentLowerBound, prePregnancyWeight + 1.5); // Minimum gain early on currentUpperBound = Math.max(currentUpperBound, currentLowerBound + 1); // Ensure upper is above lower // Cap at typical total max gain var maxRecommendedTotal = prePregnancyWeight + 16.0; idealGain.push(Math.min(currentIdealTotalGain, maxRecommendedTotal)); lowerBound.push(Math.min(currentLowerBound, maxRecommendedTotal)); upperBound.push(Math.min(currentUpperBound, maxRecommendedTotal)); // Actual gain up to current week if (i <= weeksOfPregnancy) { actualGain.push(currentWeight – prePregnancyWeight); } else { actualGain.push(null); // Don't plot future points as 'actual' } } // Ensure actual gain aligns with the current inputs if plotted // If the loop runs past weeksOfPregnancy, the last actualGain point should reflect the current state. if (weeks.includes(weeksOfPregnancy)) { actualGain[weeks.indexOf(weeksOfPregnancy)] = totalGain; } // Destroy previous chart instance if it exists if (chartInstance) { chartInstance.destroy(); } chartInstance = new Chart(ctx, { type: 'line', data: { labels: weeks, datasets: [ { label: 'Actual Weight Gain', data: actualGain, borderColor: '#28a745', // Success color backgroundColor: 'rgba(40, 167, 69, 0.2)', fill: false, tension: 0.1, pointRadius: 4, pointHoverRadius: 6 }, { label: 'Recommended Range', data: lowerBound, // Use lower bound for the start of the range band borderColor: 'rgba(0, 74, 153, 0.6)', // Primary color light backgroundColor: 'rgba(0, 74, 153, 0.1)', fill: '+1', // Fill to the next dataset (upperBound) tension: 0.1, pointRadius: 0 // Hide points for range }, { label: 'Upper Recommended Range', // This dataset is just for filling data: upperBound, borderColor: 'rgba(0, 74, 153, 0.0)', // Invisible line backgroundColor: 'rgba(0, 74, 153, 0.1)', // Fill color for the range fill: false, // Do not fill to the next dataset tension: 0.1, pointRadius: 0 } ] }, options: { responsive: true, maintainAspectRatio: true, scales: { x: { title: { display: true, text: 'Gestational Age (Weeks)' } }, y: { title: { display: true, text: 'Total Weight Gain (kg)' }, beginAtZero: true } }, plugins: { tooltip: { callbacks: { label: function(context) { var label = context.dataset.label || ''; if (label) { label += ': '; } if (context.parsed.y !== null) { label += context.parsed.y.toFixed(1) + ' kg'; } return label; } } }, legend: { labels: { // Filter out the dummy upper range dataset from the legend filter: function(legendItem, chartData) { return chartData.datasets[legendItem.datasetIndex].label !== 'Upper Recommended Range'; } } } } } }); } function updateChart(weeksData, actualGainData, lowerBoundData, upperBoundData) { var ctx = document.getElementById('weightGainChart').getContext('2d'); // Destroy previous chart instance if it exists if (chartInstance) { chartInstance.destroy(); } chartInstance = new Chart(ctx, { type: 'line', data: { labels: weeksData, datasets: [ { label: 'Actual Weight Gain', data: actualGainData, borderColor: '#28a745', backgroundColor: 'rgba(40, 167, 69, 0.2)', fill: false, tension: 0.1, pointRadius: 4, pointHoverRadius: 6 }, { label: 'Recommended Range', data: lowerBoundData, borderColor: 'rgba(0, 74, 153, 0.6)', backgroundColor: 'rgba(0, 74, 153, 0.1)', fill: '+1', tension: 0.1, pointRadius: 0 }, { label: 'Upper Recommended Range', data: upperBoundData, borderColor: 'rgba(0, 74, 153, 0.0)', backgroundColor: 'rgba(0, 74, 153, 0.1)', fill: false, tension: 0.1, pointRadius: 0 } ] }, options: { responsive: true, maintainAspectRatio: true, scales: { x: { title: { display: true, text: 'Gestational Age (Weeks)' } }, y: { title: { display: true, text: 'Total Weight Gain (kg)' }, beginAtZero: true } }, plugins: { tooltip: { callbacks: { label: function(context) { var label = context.dataset.label || ''; if (label) { label += ': '; } if (context.parsed.y !== null) { label += context.parsed.y.toFixed(1) + ' kg'; } return label; } } }, legend: { labels: { filter: function(legendItem, chartData) { return chartData.datasets[legendItem.datasetIndex].label !== 'Upper Recommended Range'; } } } } } }); } // Initial calculation on page load with default values document.addEventListener('DOMContentLoaded', function() { resetCalculator(); // Sets default values and calculates // Initial chart update with placeholder/default data if needed, but resetCalculator() calls calculateNetGain() which calls updateChartData() // So, the chart should be populated correctly after resetCalculator() });

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